The Daqing Oilfield Sazhong Development Zone with the Gas-oil Ratio

In the late stage of super high water cut development in the Sazhong Development Zone, the oilfield development rules have changed, showing a significant increase in the production gas-oil ratio. To study the factors and laws of production gas-oil ratio change, laboratory research on oil/gas/water high-pressures physical properties, a field test for single layer development, and theoretical calculation of modified oil-gas ratio were carried out. The results show that partially dissolved gas can be obtained from saturated gas crude oil by injecting water or polymer solution. In the ultra-high water cut period, especially when the water cut rises to 95%, the production gas-oil ratio will rise sharply due to the influence of gas production in water. At the same time, the ground saturation pressure difference is also an important factor affecting the production oil-gas ratio and recovery factor. Therefore, in the process of analyzing the production gas-oil ratio, it is necessary to study the influence of the ground saturation pressure difference and the dissolved gas-water ratio, especially in the ultra-high water cut stage and chemical flooding stage.